International Business Machines Corporation

Richard A Gilmour

Erick G Walton

Ronald R Uttecht

David C Thomas

Thomas J Hartswick

William Thomas Motsiff

Timothy Harrison Daubenspeck

Christopher David Muzzy

William A Klaasen

Paul J Tsang

Kerry L Batdorf

A laser alignment target is provided having a surface that is out of plane with and has substantially the same first reflectivity as an adjacent surface of the semiconductor device, and a sidewall having a second reflectivity different than the first reflectivity. The target provides sidewalls that provide contrast for finding the target despite loss of contrast created by layers of dielectric over the target and use of short wavelength light.

Laser alignment target and method

The present invention relates to an alignment mark structure for laser fusing. An alignment mark structure is formed which is comprised of image elements that are placed on different film layers in a semiconductor device. Alignment is accomplished by examining the difference in reflected energy of a laser beam as the beam traverses the alignment mark structure. By forming the alignment mark structure such that it has elements on different film layers, the reflected energy can be modulated to avoid the situation in which no difference in reflected energy is found, which would make the alignment mark invisible to the laser fusing tool. A method of applying the alignment mark structure is also disclosed.

Alignment mark structure for laser fusing and method of use

A shortened fuse link is disclosed. The fuse link comprises a first and second interconnect, with interconnects each being substantially longer than deep. The interconnects are disposed toward each other with a insulator region between them. A fusible conductor, spanning the insulator region, is attached at the top of the interconnects. The present device allows the length of the fusible conductor to be shortened, and results in a fuse link that can be consistently blown with a single laser pulse. Additionally, the fuse link can be used in a staggered layout. The staggered layout of parallel fuse links allows a high number of links in a relatively small area, with or without the use of tungsten barriers, and allows accessing all fuse links through a single fuse blow window.

Fusible links formed on interconnects which are at least twice as long

The fuse link includes a first and second interconnect, with interconnects each being substantially longer than deep. The interconnects are disposed toward each other with a insulator region between them. A fusible conductor, spanning the insulator region, is attached at the top of the interconnects. The present device allows the length of the fusible conductor to be shortened, and results in a fuse link that can be consistently blown with a single laser pulse. Additionally, the fuse link can be used in a staggered layout. The staggered layout of parallel fuse links allows a high number of links in a relatively small area, with or without the use of tungsten barriers, and allows accessing all fuse links through a single fuse blow window.

Fusible links with improved interconnect structure

The present disclosure sets forth an improved integrated circuit in which circuit elements, adjacent to a fuse, are protected by barriers positioned adjacent the fuse. In the improved integrated circuit the barriers are non-frangible, high melting point structures buried in the passivating layer, covering a wiring layer containing a fuse, and are between the fuse and adjacent circuit elements in the wiring layer structures. Also taught is a method of protecting circuit elements adjacent a fuse comprising the steps of depositing an insulating layer on the surface of a semiconductor device having active regions therein, forming a plurality of fuses and circuit elements in said layer, coating said fuses and elements with a second insulating layer, patterning said second insulating layer to form grooves between each of said fuses and any adjacent fuse or circuit element, and depositing a high melting point and non-frangible material in said grooves.

Array protection devices and method

Array protection devices and fabrication method

Array fuse damage protection devices and fabrication method

A method of fabricating a microfuse, deletable by laser pulses utilizes laser pulses of a predetermined spot diameter and beam alignment accuracy. A fusible link forming a portion of the microfuse is defined such that its length is at least equal to the sum of the laser spot diameter and the beam alignment accuracy and its width is no greater than half the laser spot diameter. A method of deleting the microfuse by laser pulses is provided where the microfuse has a predetermined composition, length and width having an axis bisecting the width and parallel to the length and is covered with a passivation layer at least 3 .mu.m thick. The method includes adjusting the diameter of the beam of laser light (i) to at least a minimum diameter of W+.DELTA.P.sub.w, where W equals the width of the microfuse fuse link and .DELTA. P.sub.w equals the accuracy of the beam in the direction of W and (ii) to no more than a maximum diameter of L+.DELTA.P.sub.L, where L equals the length of the microfuse fuse link and .DELTA.P.sub.L equals the accuracy of the beam in the direction of L.

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Colchester, VT, United States of America

Richard A Gilmour